Toward a Digital Thread and Data Package for Metals-Additive Manufacturing.

Additive manufacturing (AM) has been envisioned by many as a driving factor of the next industrial revolution. Potential benefits of AM adoption include the production of low-volume, customized, complicated parts/products, supply chain efficiencies, shortened time-to-market, and environmental sustainability. Work remains, however, for AM to reach the status of a full production-ready technology. Whereas the ability to create unique 3D geometries has been generally proven, production challenges remain, including lack of (1) data manageability through information management systems, (2) traceability to promote product producibility, process repeatability, and part-to-part reproducibility, and (3) accountability through mature certification and qualification methodologies. To address these challenges in part, this paper discusses the building of data models to support the development of validation and conformance methodologies in AM. We present an AM information map that leverages informatics to facilitate part producibility, process repeatability, and part-to-part reproducibility in an AM process. We present three separate case studies to demonstrate the importance of establishing baseline data structures and part provenance through an AM digital thread.

Potential role of advanced MRI techniques for the peritumoural region in differentiating glioblastoma multiforme and solitary metastatic lesions.

Differentiation between solitary metastatic lesions and glioblastomas, two of the most common malignant brain neoplasms, is often a diagnostic challenge. The purpose of this review is to emphasize the potential roles of advanced magnetic resonance imaging (MRI) techniques, including diffusion-based techniques, such as diffusion-weighted imaging (DWI), exponential DWI, and diffusion tensor imaging, MR perfusion, and MR spectroscopy, as well as conventional MRI, in making a distinction between glioblastomas and solitary metastases in peritumoural regions. Integration of advanced MRI features with conventional MRI, may provide valuable information for differentiating glioblastoma from solitary metastatic lesions.

Enhanced Controlled Transdermal Delivery of Ambroxol from the EVA Matrix.

To avoid the systemic adverse effects that might occur after oral administration, transdermal delivery of ambroxol was studied as a method for maintaining proper blood levels for an extended period. Release of ambroxol according to concentration and temperature was determined, and permeation of drug through rat skin was studied using two chamber-diffusion cells. The solubility according to PEG 400 volume fraction was highest at 40% PEG 400. The rate of drug release from the EVA matrix increased with increased temperature and drug loading doses. A linear relationship existed between the release rate and the square root of loading rate. The activation energy (Ea) was measured from the slope of the plot of log P versus 1000/T and was found to be 10.71, 10.39, 10.33 and 9.87 kcal/mol for 2, 3, 4 and 5% loading dose from the EVA matrix, respectively. To increase the permeation rate of ambroxol across rat skin from the EVA matrix, various penetration enhancers such as fatty acids (saturated, unsaturated), propylene glycols, glycerides, pyrrolidones, and non-ionic surfactants were used. The enhancing effects of the incorporated enhancers on the skin permeation of ambroxol were evaluated using Franz diffusion cells fitted with intact excised rat skin at 37° using 40% PEG 400 solution as a receptor medium. Among the enhancers used, polyoxyethylene-2-oleyl ether increased the permeation rate by 4.25-fold. In conclusion, EVA matrix containing plasticizer and permeation enhancer could be developed for enhanced transdermal delivery of ambroxol.

In vitro cytotoxicity tests on cultured human skin fibroblasts to predict skin irritation potential of surfactants.

Cultured human skin cells are a potentially useful model for skin irritancy testing. We have investigated the use of human skin fibroblasts for in vitro screening for skin toxicity. To assess the cytotoxic effects of surfactants, cell viability was measured by the NRU (neutral red uptake) assay and AB (Alamar blue) assay as in vitro methods. The skin irritation potential of surfactants by human skin patch test was assessed as in vivo methods. The close relationship was found between AB assay with human skin fibroblasts and human patch test (r=0.867). There was a relatively good agreement between the NRU and in vivo patch test (r=0.648). These results suggest that AB and NRU assay using cultured human fibroblast could be predictable methods for the irritancy of various surfactants in human.

Neuroprotective effect of green tea extract in experimental ischemia-reperfusion brain injury.

Eicosanoids accumulation and formation of oxygen free radicals have been implicated in the pathogenesis of ischemia/reperfusion brain injury. In the present study, we examined whether green tea extract protects against ischemia/reperfusion-induced brain injury by minimizing eicosanoid accumulation and oxygen radical-induced oxidative damage in the brain. Green tea extract (0.5%) was orally administered to Wistar rats for 3 weeks before induction of ischemia. Ischemia was induced by the occlusion of middle cerebral arteries for 60 min and reperfusion was achieved for 24 h. Infarction volume in the ipsilateral hemisphere of ischemia/reperfusion animals was 114 +/- 16 mm(3) in the 0.5% green tea pretreated animals compared to 180 +/- 54 mm(3) in left hemisphere of nontreated animals. Green tea extract (0.5%) also reduced ischemia/reperfusion-induced eicosanoid concentration: Leukotriene C(4) (from 245 +/- 51 to186 +/- 22), prostoglandin E(2) (from 306 +/- 71 to 212 +/- 43) and thromboxane A(2) (327 +/- 69 to 251 +/- 87 ng/mg protein). Ischemia/reperfusion-induced increases of hydrogen peroxide level (from 688 +/- 76 to 501 +/- 99 nmole/mg protein), lipid peroxidation products (from 1010 +/- 110 to 820 +/- 70 nmole/mg protein) and 8-oxodG formation (from 1.3 +/- 0.3 to 0.8 +/- 0.2 ng/microg DNA, x10(-2)) were also reduced. Moreover, 0.5% green tea extract also reduced the apoptotic cell number (from 44 +/- 11 to 29 +/- 1 in the striatum, and from 72 +/- 11 to 42 +/- 5 apoptotic cells/high power field in the cortex region). Green tea extract pretreatment also promoted recovery from the ischemia/reperfusion-induced inhibition of active avoidance. The present study shows that the minimizing effect of green tea extract on the eicosanoid accumulation and oxidative damage in addition to the reduction of neuronal cell death could eventually result in protective effect on the ischemia/reperfusion-induced brain injury and behavior deficit.